1. Field of the Invention
The present invention relates to a method of flushing a water closet by feeding water and air from a pressure vessel through an outflow valve and an outflow conduit into a toilet bowl.
It also relates to flushing apparatuses for water closets of the kind including a container for the storage of flushing water, which container is provided with an infeed line intended for connection to water main such to communicate said container with the water main, which container is provided further with an outlet line leading to the bowl of said water closet, in which outlet line there is provided a flushing valve which in its opened position establishes communication between said container and said water closet bowl.
2. Description of the Prior Art
Such flushing apparatuses for water closets are commonly known. The water intended for flushing is stored thereby in an open container usually covered by a removable cover for esthetic reasons. The arrangement of so-called low mounted flushing containers, which containers are mounted at the height immediately above the water closet bowl and are connected with a short elbow pipe to the inlet of this water closet bowl, is generally known. Also known is the somewhat older arrangement having a container mounted relatively high above the water closet bowl, i.e. at a vertical distance from 1.20 meters to 1.50 meters above the water closet bowl. Such high hanging containers are connected by the agency of a flushing line including an inlet elbow to the water closet bowl. The flushing water stemming from the water mains of e.g. the community waterworks is stored in these containers and in order to flush the water closet the container is emptied into the bowl thereof. The flushing pressure is governed by the static height of the stored water and is comparatively low. Conclusively, the distribution effect of the water jet in the bowl is quite small. In order to secure a hygenic operation large water quantities are needed in the range of between 9 liters and 14 liters per flushing process depending on the prevailing flushing apparatus installed. Water storage containers located high above the water closet bowl lead to a higher kinetic energy of the water and thus their water consumption is 10% to 15% lower than such of above mentioned low mounted water containers. However, such high hanging water containers result in higher investment costs when installing the flushing line and are hardly used any longer due to esthetic considerations.
In order to provide an adequate volume of water during the short time span as needed during flushing of the water closet all such flushing apparatuses having water storage containers must be provided with large pipe cross sections at their outlet portion. Furthermore, in order to control the filling of the water storage container a mechanism including a float is necessary. This leads to the fact that water closets having such flushing water storage containers incorporate comparatively intrinsic designs. A further drawback of these known systems is their long time span needed for refilling the storage container, namely a time span of about 70 seconds, which does not allow a fast repetitious flushing of the water closet. Furthermore, the volume flow of the flushing water can usually not be controlled. Due to the necessary and known designs the water storage container is practically completely emptied at every flushing procedure, which adds together with the small pressure of the water jet to the extremely high water consumption.
So-called pressure flushing apparatuses have been known since a considerable time, which pressure flushing apparatuses are directly coupled to a water main without a container arranged between the water closet bowl and the water mains and thus flush the water closet at the total line pressure of about 4.5 bar. These flushing apparatuses generate a high water speed and accordingly a satisfactory distribution of the water jet. The water volume used for each flushing procedure can be controlled to a large extent and accordingly may be held at a low volume.
These pressure flushing apparatuses feature, however, the drawback in that in order to secure a large water volume flowing with high speed all infeed lines must comprise cross-sectional areas of the pipes which exceed considerably the standard cross-sectional areas of water pipes.
A more serious problem is the fact that when operating a pressure flushing apparatus sudden pressure changes are generated and transmitted within the complete water pipe network. This follows from the direct connection of the pressure flushing apparatus into the water main net and because water is used as pressure medium. When opening the valve of the pressure flushing apparatus a sudden pressure drop is generated and when closing the flushing valve a sudden increase of pressure is generated. These pressure changes are transmitted shock-wavelike throughout the water column. This leads to a large mechanical stress of the water pipes, which may lead specifically at older pipes rather easily to pipe ruptures.
In the DE-PS No. 108 131 there is disclosed a flushing apparatus mounted in the floor under a toilet bowl and operating during the flushing step by utilizing air as pressurized medium. An air pressure vessel is mounted in the floor and is provided with an upwards leading long pipe for the flushing water, which pipe opens into the toilet bowl. The efficiency of this flushing apparatus is, however, quite insufficient because the air pressure in the air pressure vessel must act against a large water column and, therefore, can generate a small output only.
The DE-GM No. 1 934 598 discloses a flushing apparatus which operates on an injector basis, too. This flushing apparatus aspirates ambient air directly from the flushing pipe. An upright cylindrical container is provided for the storage of the flushing water and an air cushion space is provided above the flushing water. The injector itself is arranged within the flushing water and consists basically of a block having a through bore which extends axially relative to the axis of the container, which through bore feeds water and air into the inner space of the container. The middle section of the axial bore in the block has a restricted cross section and this restricted part is connected via a thin channel to an air aspirating bore. As mentioned above, this aspirating bore extends via a connecting conduit into the flushing pipe. However, such an injector will also not operate satisfactorily. The stream of air drawn is accelerated by the restriction to a multiple speed of flow; however, in the immediately following section of the axial bore having a growing diameter it is decelerated and flows from this point into the flushing water, in which it must work against the pressure of the water column. If now, during flushing, outflowing water generates a resistance, the injector will be practically inoperable. Because, furthermore, the aspiration bore in the air infeed communicates with the flushing pipe, water only is initially transported upon opening of the flushing valve. Accordingly, the injector does initially draw practically no air, but rather merely water out of the aspirating bore which communicates with the flushing or discharge, respectively, pipe. Air is transported only after the flushing water has completely flown into the toilet bowl and the flushing valve was closed. This follows, however, in that during the time span of highest operational conditions the injector cannot draw or aspirate, respectively, any air. Accordingly, the flushing operation is not improved in spite of a high water consumption and of a design which due to the through bores is relatively complicated and additionally trouble prone. The ball valves used do not always ensure a safe seal and the injector which is mounted in the container is accessible with difficulties only, which obviously leads to difficulties in the maintenance of the apparatus.